/Engine/Source/Runtime/HeadMountedDisplay/Public/IHandTracker.h
bool GetAllKeypointStates ( EControllerHand Hand, [TArray](API\Runtime\Core\Containers\TArray)< FVector > & OutPositions, [TArray](API\Runtime\Core\Containers\TArray)< FQuat > & OutRotations, [TArray](API\Runtime\Core\Containers\TArray)< float > & OutRadii ) const